The updrafts that have built the storms are gone. The air and water that has been lifted high into the atmosphere now begins to descend toward the ground. At first there may be some evaporational cooling of the air mass. This makes the air heavier and it descends more rapidly.

As the air dries and speeds up, it begins to warm as it descends. Descending air can warm at 5 to 10 degrees per thousand feet of descent depending on conditions. This is similar to a Chinook Wind effect in the lee of the Rockies.

As the downdraft hit the ground in Pierre, the winds kicked up and temperatures shot up to 90 degrees at 2 in the morning!

Heat bursts are almost impossible to detect and forecast. There is really no good way to measure what’s coming at you from 10,000 feet straight above you in the middle of the night.

About the blogger

Paul Huttner is chief meteorologist for Minnesota Public Radio. Huttner has worked TV and radio stations in Minneapolis, Tucson and Chicago. Paul is a graduate of Macalester College in St. Paul and holds a bachelor’s degree in geography with an emphasis in meteorology.